1. Field of the Invention
The present invention relates to a multi-eye image pickup device and adjusting method and device therefor, and further relates to a system and a method for adjusting image areas of imaging units of the multi-eye image pickup device.
2. Description of the Related Art
A multi-eye image pickup device is known. In this kind of the multi-eye image pickup device, two optical systems for shooting are disposed at a predetermined interval to take two images, which have parallax, with a CCD image sensor and so forth. By the multi-eye image pickup device, it is possible to obtain distance information of a subject in a depth direction. The distance information is utilized for high-accuracy image recognition in which a contour and so forth of the subject are considered. For example, two face images having parallax are taken by using the multi-eye image pickup device having a pair of optical systems, which are horizontally disposed. By performing person authentication on the basis of the taken face images, it is possible to utilize the multi-eye image pickup device as a security device for managing person entering and leaving a room in a condominium, a company and so forth.
In the multi-eye image pickup device, it is necessary to mutually adjust optical axes of the shooting optical systems with great accuracy. For instance, in the multi-eye image pickup device used as the security device, the optical axes of the shooting optical systems, which are horizontally disposed, are adjusted so as to make the optical axes intersect at a fixed point of a shooting length.
In the multi-eye image pickup device (stereoscopic image pickup device) described in Japanese Patent Laid-Open Publication No. 8-317424, each of shooting optical systems is loaded with a zoom-type taking lens. Regarding the respective optical systems, a shift amount of optical axes is measured and stored in advance relative to each focal length. At a time of shooting, the focal length of the taking lens is detected and a clip area of a taken image is controlled in accordance with the shift amount of the detected focal lengths. In virtue of this, the optical axes of the obtained images are prevented from shifting.
In the multi-eye image pickup device used as the security device, the optical axes of the respective shooting optical systems are adjusted so as to make the optical axes intersect at the fixed point of the shooting length. However, in a case that the subject is someone's face, the optical axes are adjusted so as to intersect at the center of both eyes similarly to a focal point. Thus, the center of both eyes of a crossly taken face becomes the center of a shooting area, so that images of a cheek, an ear and so forth located at a side portion of the face are biased to an end of the shooting area. In the worst case, there arises a problem in that these parts protrude out of the shooting area and it becomes impossible to perform the person authentication.
The above problem is similarly caused in a case that the image is clipped to correct the shift of the optical axes such as described in the above-noted Publication No. 8-317424. Incidentally, it is considerable that the shooting area and an image clip area are broadly set. In this case, however, there arises a problem in that extra image increases besides the image to be recognized. Due to this, it takes a longer time for recognition processing. Further, there arises another problem in that the image clip area might be larger than the shooting area.
In the meantime, Japanese Patent Laid-Open Publication No. 2001-242521 also teaches the multi-eye image pickup device (stereoscopic image pickup device). It is desirable that two images taken by the multi-eye image pickup device have no positional deviation except for the parallax. In fact, however, the deviation is caused within a range of mechanical attachment accuracy. In view of this, the stereoscopic image pickup device described in the above-noted Publication No. 2001-242521 includes three adjustment screws for supporting a circuit board to which a CCD is attached. An inclination and so forth of the circuit board are changed in accordance with insertion amounts of the adjustment screws to correct the positional deviation.
However, there arises a problem in that an adjusting operation of this case takes a lot of labor. In the adjusting operation, the images are confirmed and adjusted while the insertion amounts of the screws are changed little by little. Especially, in a case the stereoscopic image pickup device is used as an authentication camera and a security camera, it is likely to cause the positional deviation at a time of transportation thereof. Thus, it is preferable that the adjustment is performed just before attaching the stereoscopic image pickup device to a predetermined installation place of another equipment, a room and so forth. In order to simplifying the attachment operation as well, it is strongly desired that the positional deviation of the images can be more easily adjusted.